bascule de visibilité Search & Display Options

Tout Sélectionner    Désélectionner
 |   | 
Détails
   print
  Enregistrements Liens
Auteur Braham, C.B.; Freon, P.; Laurec, A.; Demarcq, H.; Bez, N. url  doi
openurl 
  Titre New insights in the spatial dynamics of sardinella stocks off Mauritania (North-West Africa) based on logbook data analysis Type Article scientifique
  Année 2014 Publication Revue Abrégée Fisheries Research  
  Volume 154 Numéro Pages 195-204  
  Mots-Clés  
  Résumé Sardinella spp. are the main species fished in Mauritanian waters. Logbook data (1991&8211;2009) were used to standardise CPUE. This clearly revealed that the abundance of sardinella peaked in the warm season (July&8211;September) which is the main, if not the only significant spawning season for round sardinella.

This study does not directly confirm or falsify the common belief that the adults migrate from the Senegalese EEZ up to north of the 21° N latitude, but it presents a variety of new hypotheses. If a single transboundary stock exists, part of its individuals, or a sub-stock, is probably more sedentary and remains in the permanent upwelling area located in northern Mauritania and southern Morocco.

Between years, changes in abundance index are dominated by a decrease from 1996 to 2006, depending on the months taken into account, and especially whether or not the warm (spawning) season is considered. For a given month, the spatial distribution of sardinella shows limited differences between years. In the southernmost latitudes of the Mauritanian EEZ the seasonal pattern, which is dominated by high catch rates during the warm season, is much stronger after the year 2001, and then tended to increase year after year.

Changes in species distribution and abundance during the twenty-year study period are difficult to relate to environmental dynamics. However, an inversion of the upwelling trend was observed in 2001, matching a change in the seasonality of sardinella catches, although the causality between the two phenomena could not be established. The increase in the abundance index of sardinella in the last five years, particularly during most of the core fishing season (July&8211;September) might be due to favourable oceanographic conditions (higher upwelling index) and/or changes in the fishing strategies or efficiency. Before annual indices of abundance can be used in the future, it will be necessary to better understand possible changes in catchability during the warm/spawning season.
 
  Adresse  
  Auteur institutionnel Thèse  
  Editeur Lieu de Publication Éditeur  
  Langue eng Langue du Résumé Titre Original  
  Éditeur de collection (up) Titre de collection Titre de collection Abrégé  
  Volume de collection Numéro de collection Edition  
  ISSN 0165-7836 ISBN Médium  
  Région Expédition Conférence  
  Notes Approuvé pas de  
  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 1147  
Lien permanent pour cet enregistrement
 

 
Auteur Coll, M.; Carreras, M.; Ciércoles, C.; Cornax, M.-J.; Gorelli, G.; Morote, E.; Sáez, R. url  doi
openurl 
  Titre Assessing Fishing and Marine Biodiversity Changes Using Fishers' Perceptions: The Spanish Mediterranean and Gulf of Cadiz Case Study Type Article scientifique
  Année 2014 Publication Revue Abrégée PLoS ONE  
  Volume 9 Numéro 1 Pages  
  Mots-Clés  
  Résumé BackgroundThe expansion of fishing activities has intensively transformed marine ecosystems worldwide. However, available time series do not frequently cover historical periods.MethodologyFishers' perceptions were used to complement data and characterise changes in fishing activity and exploited ecosystems in the Spanish Mediterranean Sea and Gulf of Cadiz. Fishers' interviews were conducted in 27 fishing harbours of the area, and included 64 fishers from ages between 20 to >70 years old to capture the experiences and memories of various generations. Results are discussed in comparison with available independent information using stock assessments and international convention lists.Principal FindingsAccording to fishers, fishing activity substantially evolved in the area with time, expanding towards deeper grounds and towards areas more distant from the coast. The maximum amount of catch ever caught and the weight of the largest species ever captured inversely declined with time. Fishers (70%) cited specific fishing grounds where depletion occurred. They documented ecological changes of marine biodiversity during the last half of the century: 94% reported the decline of commercially important fish and invertebrates and 61% listed species that could have been extirpated, with frequent mentions to cartilaginous fish. Declines and extirpations were in line with available quantitative evaluations from stock assessments and international conventions, and were likely linked to fishing impacts. Conversely, half of interviewed fishers claimed that several species had proliferated, such as cephalopods, jellyfish, and small-sized fish. These changes were likely related to trophic cascades due to fishing and due to climate change effects. The species composition of depletions, local extinctions and proliferations showed differences by region suggesting that regional dynamics are important when analysing biodiversity changes.Conclusions/SignificanceUsing fishers' perceptions, fishing and ecological changes in the study area were documented. The recovery of local ecological knowledge provides valuable information complementing quantitative monitoring and evaluation surveys.  
  Adresse  
  Auteur institutionnel Thèse  
  Editeur Lieu de Publication Éditeur  
  Langue Langue du Résumé Titre Original  
  Éditeur de collection (up) Titre de collection Titre de collection Abrégé  
  Volume de collection Numéro de collection Edition  
  ISSN ISBN Médium  
  Région Expédition Conférence  
  Notes Approuvé pas de  
  Numéro d'Appel LL @ pixluser @ collection 380  
Lien permanent pour cet enregistrement
 

 
Auteur Freon, P.; Avadi, A.; Chavez, R.A.V.; Ahon, F.I. url  doi
openurl 
  Titre Life cycle assessment of the Peruvian industrial anchoveta fleet : boundary setting in life cycle inventory analyses of complex and plural means of production Type Article scientifique
  Année 2014 Publication Revue Abrégée International Journal of Life Cycle Assessment  
  Volume 19 Numéro 5 Pages 1068-1086  
  Mots-Clés Attributional LCA; Complex production system; Environmental impacts; Fishing vessel; Fuel use; Life cycle inventory  
  Résumé This work has two major objectives: (1) to perform an attributional life cycle assessment (LCA) of a complex mean of production, the main Peruvian fishery targeting anchoveta (anchovy) and (2) to assess common assumptions regarding the exclusion of items from the life cycle inventory (LCI). Data were compiled for 136 vessels of the 661 units in the fleet. The functional unit was 1 t of fresh fish delivered by a steel vessel. Our approach consisted of four steps: (1) a stratified sampling scheme based on a typology of the fleet, (2) a large and very detailed inventory on small representative samples with very limited exclusion based on conventional LCI approaches, (3) an impact assessment on this detailed LCI, followed by a boundary-refining process consisting of retention of items that contributed to the first 95 % of total impacts and (4) increasing the initial sample with a limited number of items, according to the results of (3). The life cycle impact assessment (LCIA) method mostly used was ReCiPe v1.07 associated to the ecoinvent database. Some items that are usually ignored in an LCI's means of production have a significant impact. The use phase is the most important in terms of impacts (66 %), and within that phase, fuel consumption is the leading inventory item contributing to impacts (99 %). Provision of metals (with special attention to electric wiring which is often overlooked) during construction and maintenance, and of nylon for fishing nets, follows. The anchoveta fishery is shown to display the lowest fuel use intensity worldwide. Boundary setting is crucial to avoid underestimation of environmental impacts of complex means of production. The construction, maintenance and EOL stages of the life cycle of fishing vessels have here a substantial environmental impact. Recommendations can be made to decrease the environmental impact of the fleet.  
  Adresse  
  Auteur institutionnel Thèse  
  Editeur Lieu de Publication Éditeur  
  Langue Langue du Résumé Titre Original  
  Éditeur de collection (up) Titre de collection Titre de collection Abrégé  
  Volume de collection Numéro de collection Edition  
  ISSN 0948-3349 ISBN Médium  
  Région Expédition Conférence  
  Notes Approuvé pas de  
  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 1148  
Lien permanent pour cet enregistrement
 

 
Auteur Coll, M.; Carreras, M.; Cornax, M.J.; Massuti, E.; Morote, E.; Pastor, X.; Quetglas, A.; SàeZ, R.; Sobrino, I.; Torres, M.A.; Tudela, S.; Harper, S.; Zeller, H.; Pauly, D. url  openurl
  Titre Closer to reality : reconstructing total removals in mixed fisheries from Southern Europe Type Article scientifique
  Année 2014 Publication Revue Abrégée Fisheries Research  
  Volume 154 Numéro Pages 179-194  
  Mots-Clés  
  Résumé Underestimation of catches is especially important in countries where fishing fleets are highly diversified, the enforcement of fishery management is low, data availability is poor, and there is high demand for fish products in local markets. This is the case for southern European and Mediterranean regions. Adapting a catch-reconstruction approach, we estimated the total removals of marine resources by Spain for the Spanish Mediterranean Sea and Gulf of Cadiz regions from 1950 to 2010. We collected available information from scientific publications, the grey literature and secondary sources of information to complement officially reported catch data. We assessed missing catch sectors as time-point estimates, used as anchor points of reliable data upon which we then estimated total catch using interpolation to fill in the periods for which quantitative data were missing. Unreported removals and discards represented important portions of total removals in the study area. They accounted for, on average, 43% of total removals between 1950s and 2010, and were composed of black market sales, subsistence fishing, artisanal fishing, recreational fishing and illegal catch, in addition to discarding. By the late 2000s, recreational fishing was the most important sector for unreported landings (similar to 36%), followed by black market sales (similar to 32%), subsistence fishing (similar to 17%), unreported artisanal fishing (similar to 12%) and illegal catch (similar to 2%). The overall catch trend differed from the official trend highlighting that the depletion of marine resources in the region started earlier than previously observed. The catch composition changed with time, with a higher diversification of species in fish markets with time. These results indicate an earlier trend towards expansion of fisheries and depletion of marine resources.  
  Adresse  
  Auteur institutionnel Thèse  
  Editeur Lieu de Publication Éditeur  
  Langue eng Langue du Résumé Titre Original  
  Éditeur de collection (up) Titre de collection Titre de collection Abrégé  
  Volume de collection Numéro de collection Edition  
  ISSN 0165-7836 ISBN Médium  
  Région Expédition Conférence  
  Notes Approuvé pas de  
  Numéro d'Appel LL @ pixluser @ collection 381  
Lien permanent pour cet enregistrement
 

 
Auteur Freon, P.; Avadi, A.; Soto, W.M.; Negron, R. url  doi
openurl 
  Titre Environmentally extended comparison table of large-versus small- and medium-scale fisheries : the case of the Peruvian anchoveta fleet Type Article scientifique
  Année 2014 Publication Revue Abrégée Canadian Journal of Fisheries and Aquatic Sciences  
  Volume 71 Numéro 10 Pages 1459-1474  
  Mots-Clés  
  Résumé Literature on small-scale fisheries usually depicts them as preferable over large-scale-industrial fisheries regarding societal benefits (jobs, jobs per investment) and relative fuel efficiency (e. g., Thomson 1980). We propose an environmentally extended Thomson table for comparing the Peruvian anchoveta (Engraulis ringens) fleets of purse seiners, backed up by methodological information and augmented with life cycle assessment (LCA)-based environmental performance information, as a more comprehensive device for comparing fleets competing for the same resource pool. Findings from LCA and a previous study on the anchoveta steel fleet together allowed characterizing the whole Peruvian anchoveta fishery. These results, along with socioeconomic indicators, are used to build an environmentally extended Thomson table of the fleet's main segments: the steel industrial, the wooden industrial, and the wooden small-and medium-scale (SMS) fleets. In contrast with the world figure, the Peruvian SMS fleets show a fuel performance nearly two times worse than the industrial fleets, due to economies of scale of the latter (although the small-scale segment itself (<10 m(3)) performs similarly to the industrial steel fleet). Furthermore, the absolute number of jobs provided by the industrial fisheries is much larger in Peru than those provided by the SMS fisheries. This is due to the relatively larger development of the industrial fishery, but as in previous studies, the SMS fleets generate more employment per tonne landed than the industrial fleet, as well as more food fish and less discards at sea.  
  Adresse  
  Auteur institutionnel Thèse  
  Editeur Lieu de Publication Éditeur  
  Langue Langue du Résumé Titre Original  
  Éditeur de collection (up) Titre de collection Titre de collection Abrégé  
  Volume de collection Numéro de collection Edition  
  ISSN ISBN Médium  
  Région Expédition Conférence  
  Notes Approuvé pas de  
  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 1149  
Lien permanent pour cet enregistrement
Tout Sélectionner    Désélectionner
 |   | 
Détails
   print

Save Citations:
Export Records: